This invention is generally directed to apparatus for use at junctures of chords of a space frame grid, and more particularly, to a joint connector for use in a space frame system.
The use of space frame grids, particularly in large buildings, is known. Such space frame grids have been found to be cost effective in large buildings having supports widely spaced and few in number. Space frame grids can also be used when the mechanical services, vent ducts and gas and water pipes need be in the roof.
The basic geometry of the space frame presents an upper grid comprising an upper layer of support pipes/chords and a lower layer of the same. The upper and lower layers of pipes are at right angles one to the other. The lower grid presents a similar pipe/chord arrangement. A plurality of joint connectors secure the intersection of the layers of the support pipes in the upper and lower grids. Diagonal struts or chords then extend between the joint connectors of the upper and lower grids. The relative upper and lower grid arrangements can be of various relative displacements such as square-on-square offset, square-on-square offset diagonally, square-on-larger-square, etc.
The chosen relative grid arrangement will depend on various criteria including the manner of grid support, the type of loads placed thereon, the desired force patterns on the grid arrangement and aesthetic desires.
Steel pipes are commonly used in the construction of space frame grids, the thickness of which depends on the desired load characteristics. It is recognized that the jointing of the pipes in and between the grids is a major problem in the construction of space frames. In some cases it may be necessary to construct the various grid arrangements on site which can be relatively expensive. Thus, it is recognized that it is cost-effective to do as much fabrication of the space frame in the workshop and on the ground as possible. It thus is most desirable to assemble the grids and interconnect the same prior to lifting the assembled space frame into its functional position by a crane or the like.
Thus, it is desirable to have joint connectors which allow for such a cost-effective assembly. Each joint connector should secure the intersection of the upper and lower support pipes of each grid while providing structure to extend support chords between the upper and lower grids.
Problems can arise in the connection of the diagonal chord between these upper and lower grids if the forces acting along the diagonal chords are directed to points outside the center of the joint connector and/or the intersecting chords. If so, eccentric forces will arise which can lead to a degradation in the loading capacity and/or quality of the space frame.
In response thereto I have invented a joint connector which provides means to secure in the shop the intersection of the transverse chords of the upper and lower frames and connect such frames. My joint connectors present a plurality of upwardly and/or downwardly extending chord mounting flanges at the four corners of each connector. In turn, diagonally extending chords are connected between each flange so as to provide the desired chord relationship between the upper and lower grids. A second embodiment of the joint connector is utilized which provides a spacer/brake plate between the mounting flanges. This plate precludes the diagonally extending chords from being displaced beyond a desired relationship between the upper and lower grids. The joint connectors are easily connected to the intersection of the transverse pipes of each grid as well as to the diagonally extending chords in a manner which allows for a significant amount of off-site and/or on-ground construction. My joint connectors allow for the forces acting along the diagonal chords to be directed through the center thereof so as to delimit and control any asymmetric forces. As such, the connectors allow for cost-effective construction of space frame systems.
It is therefor a general object of this invention to provide a joint connector for utilization in space frame systems.
Another object of this invention is to provide a joint connector, as aforesaid, which can be easily used for off-site and/or on-ground construction of space frame systems.
A further object of this invention is to provide a joint connector, as aforesaid, which utilizes a plurality of chord mounting flanges or plates extending towards the opposed upper or lower grid of the space frame system.
Another object of this invention is to provide a joint connector, as aforesaid, which is easily shop welded to the intersection of the transverse pipes of the upper or lower grids.
Still a further object of this invention is to provide a joint connector, as aforesaid, which easily connects and maintains the diagonal chords in a desired extension between the upper and lower grids of the space frame system.
Another object of this invention is to provide a joint connector, as aforesaid, which directs the lines of force acting along the diagonal chords through the center of the joint connector.
A still further object of this invention is to present a joint connector, as aforesaid, in which on-site connections are made by bolts or the like.
Another object of this invention is to provide a joint connector, as aforesaid, which provides a structural connection between transversely extending pipes of a space frame grid.
Still another object of this invention is to provide a joint connector, as aforesaid, which provides means for structurally connecting the diagonal chords of a space frame system.
Another object of this invention is to provide a joint connector, as aforesaid, which allows for the forces thereon to be directed to a common point so as to eliminate or control any eccentric connection problems.
A further object of this invention is to provide a joint connector, as aforesaid, which comprises a plurality of brackets allowing for economical and easy assembly and use.
A still further object of this invention is to provide a joint connector, as aforesaid, which has a configuration providing for each connection thereof to be leveled upon assembly.
Other objects and advantages of this invention will become apparent from the following description taken in connection with the accompanying drawings, wherein is set forth by way of illustration and example, first and second embodiments of this invention.